Electrical connector means and method of manufacture



9 J. a. HATFIELD ETAL 3,420,087

ELECTRICAL CONNECTOR MEANS AND METHOD OF MANUFACTURE Original FiledJ uly25, 1963 I of? Sheet J'ouu G Han-nun BY Roan-r M. Numam 969 J. G.HATFIELD ETAL 3,420,087

ELECTRICAL CONNECTOR MEANS AND METHOD OF MANUFACTURE Original Filed July25, 1963 Sheet INVENTOR. JoHN G Hmneu: BY PQBERT M.Munnm J. G. HATFIELDET AL Jan. 7, 1969 :HECTRICAL CONNECTOR MEANS AND METHOD OF MANUFACTUREOriginal Filed July 25, 1963 Sheet D V- mum mm w 1H m .m a Twp-M Y 8Sheet 4 01 7 J. G. HATFIELD ETAL Original Filed July 25, 1963 INVENTOR.JOHN G. Hmrmo BY Poaewr N. Mueqm Jan. 7, 1 9 J. G. HATFIELD L 3,420,087

ELECTRICAL CONNECTOR MEANS AND METHOD OF MANUFACTURE ori inal Filed July25, 1965 Sheet 5 of 7 :9: Joan G. Herman BY Renew M. Muzem m- 7. 1969'J. cs. HATFIELD ETAL 3,4

ELECTRICAL CONNECTOR MEANS AND METHOD OF IANUFAGTURE ori inal Filed July25, 1963 of '7 v Sheet ,INVENTOR. JOHN G. Hmntu: BY 1205mm P). MURRAY n-7, 9 J. G. HATFIELD ETAL 3,420,087

ELECTRICAL CONNECTOR MEANS AND METHOD OF MANUFACTURE Original Filed July25, 1963 Sheet 7 or 7 INVENTOR- Jonu 6- Human By 205121 N. MURRHY UnitedStates Patent 3,420,087 ELECTRICAL CONNECTOR MEANS AND METHOD OFMANUFACTURE John G. Hatfield, Camp Hill, and Robert M. Murray,Elizabethtown, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Original application July 25, 1963, Ser. No. 298,002, now Patent No.3,288,915, dated Nov. 29, 1966. Divided and this application July 29,1966, Ser. No. 581,674

U. S. C]. 72338 5 Claims Int. Cl. B26d 3/00 ABSTRACT OF THE DISCLOSUREAn electrical connector is disclosed which is formed of relatively thinsheet metal to include a one piece configuration having a rigid postsection with four sharp corners to receive a wrapped wire therearoundand a tubular support portion for mounting purposes. The connectorincludes a further portion extending from the mounting portion which isreadily deformable or may be made to provide a spring function. Theconnector post section is formed by impact compressing fiat stock into aU-shaped configuration between dies within a channel having fixed sidewalls to a point of extrusion of the outer edges of the post.

This is a division of my application, Ser. No. 298,002, filed July 25,1963 and now Patent No. 3,288,915, which is a continuation in part of anapplication Ser. No. 259,192 filed Feb. 18, 1963 now US. Patent No.3,288,915.

This invention relates to an improved electrical connector and to amethod for manufacturing such connector. More particularly, thisinvention relates to means and method of manufacture of an electricalconnector of a type having characteristics suitable for use inpoint-topoint wiring applications and at the same time havingcharacteristics suitable for use in other types of connections callingfor either resiliency or formability of connector metal material.

As with solder, weld or crimp type electrical connections in general,the object of the point-to-point wiring connection is broadly to providea stable, low resistance, conductive path between electrical circuits.The conductive path generally utilized is a length of relatively smallinsulated electrical conductor mechanically and electrically secured todistinct and separate points most commonly represented by conductivemetal post members held in an insulating board and interconnectedthrough such board to other individual connector means in turn connectedto the electrical circuits sought to be interconnected.

Qualifying this general objective of point-to-point wiring applicationsare further factors related to the type of connection being made at eachpoint which in turn dictate other requirements including possible highconnection density (related to size and shape), reliability ofconnection, longevity, and cost, both of connector and of making theconnection. The particular type of connection utilized sets up furtherrequirements. For example, the wire-wrap connection adds specializedcriteria related to radial forces which the connector must withstandduring the application of wire-wrap turns and to the resistance againstcold flow of the connector during the life of the wire-wrap connection.As a further example, there exist newly developed clip-on typeconnections which demand that any point-to-point wiring terminal postmust be capable of supporting axial application forces and provide acertain mechanical resistance to assure a proper maintenance ofconductor interface.

As described in detail in U.S. Patent No. 2,759,166 to R. F. Mallina,one specialized requirement relates to the material characteristics of aterminal post utilized in conjunction with wire-wrap techniques whichoperate to set up radial shearing and tensioning forces exerted by thewire during and after its application upon the terminal post. Thematerial characteristics of the post must be such that the postdimensions will not be altered by cold flow under the forces developedby the wire under tension to an extent permitting an ultimate relaxationof the wirewrap thereby resulting in the loss of the potential energy orelastic reserve stored in the wire-wrap turns and in the post to cause afailure in continuity between wire and post. As further noted in theMallina patent, a second basic requirement for wire-wrap terminationrelates to the presence of an abrupt edge enabling the locking-in of thetensional forces of the wire to the post with a resulting stableinterface contact area therebetween.

Further specialized requirements for satisfactory wirewrap connectionsmay include the factors described by W. P. Mason in US. Patent No.2,870,241 wherein use of particular surface materials incorporated intoa terminal post in conjunction with a sufficient force of contact areutilized to provide a diffusion between wire and post material resultingin an improved connection. Yet a further desirable feature for terminalposts being used for wirewrap applications is outlined in US. Patent No.2,998,590 to F. G. Buhrendorf wherein there is described a method ofmaking wire-wrap connections which involves prestressing the terminalpost by twisting or rotational movement as the wire is being wrapped intension about such post.

In US. patent application Ser. No. 171,074 filed Feb. 5, 1962 in thename of Robert F. Cobaugh, now US. Patent No. 3,239,918, there isdescribed a different type of electrical connector having a capabilityanalogous to that of the wire-wrap technique with respect topoint-topoint wiring applications. This approach features a terminalpost adapted to receive a clip member driven with considerable forcethereover to wedge an electrical conductor into a stable, low resistanceinterface contact with the post member. The Cobaugh type clip has thefurther advantage of being capable of use with insulated conductorswithout a formal step of insulation stripping; the clip in being drivenonto the terminal post operating to break and separate the insulationexposing the conductor material for contact. As will be appreciated froma review of the above-mentioned application, the use of the describedclip involves a wedging operation wherein considerable longitudinal oraxial forces are applied to the post. When the Cobaugh clip is appliedby hand tools or even by automatic point-to-point wiring machines,slight oblique forces may result operating on the terminal postresulting in shearing forces being applied to the post. During the lifeof Cobaugh type connections the terminal post must be capable ofmaintaining its cross sectional configuration to an extent sufficient toprovide an elastic reserve between clip and post holding the conductortherebetween in a stable interface contact.

Thus it is with both wire-wrap and clip type connections that theparticular terminal post construction utilized must withstand certainforces during the application of a particular connection and thereafterduring the life of such connection. The prior art answer to theforegoing requirements has been to provide a relatively thick solid postmember as, for example, a post 30 thousandths of an inch or greater.Because of this, the material characteristics of the post memberutilized have prevented the use of the post material for anything butthe most limited additional functions such as providing the postmounting means. In even this use, it has been found necessary to embossor further reduce the post material thickness to a form mounting tabmembers which can be practically bent or deformed to lock the terminalpost within an insulat- -ing board aperture. Further due to therelatively thick post material utilized in the prior art, it hasheretofore been necessary to provide other and distinct connectors inapplications wherein the connection made to the post must lead to aconnection of the disconnect type. In addition to the multiplication ofparts to perform a given number of connections, this practice inherentlyreduces the reliability of a given connection by increasing theopportunity for connection failure.

Accordingly, an object of the present invention is to provide animproved electrical connector having material qualities complementary towire-wrap, clip type and other terminations and to a method of formingsuch connector from relatively thin, flat metal sheet material.

A further object of the invention is to provide an improved terminalpost construction having geometrical and material characteristics whichenhance the electrical and mechanical connection formed by standardpoint-to-point wiring procedures.

Another object of invention is to provide a universal terminal post andmethod of manufacturing such post permitting economy of use andmanufacture.

Still another object of invention is the provision of a connectorincluding a post section and a mounting section interconnected by atransition section adapted to hold the post section against substantialdeformation during the application of conductors thereon.

A still further object of invention is to provide an improved terminalpost construction of relatively thin, flat metal sheet material havingqualities suitable for use in other types of electrical connectors.

Still another object of invention is the provision of a connector havingas an integral structure a post section suitable for wire-wrap or othertype connections and a further section having material characteristicsdesirable for securing the connector in a mounting board.

Yet another object of the invention is the provision of a connectorhaving as an integral structure a terminal post section and a furthersection formed to provide a locking feature to secure the connector inan insulating board.

Another object of the invention is the provision of a connector havingas an integral structure a post section suitable for wire-wrap or othertype connections and a further section of suitable resiliency toaccommodate a spring engagement in a disconnect type connection with afurther connector.

Yet another object of invention is the provision of a connector havingas an integral structure a terminal post section and a further sectionadapted to be crimped to provide an electrical and mechanical connectionwith a conductor.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there are shown and described illustrative embodiments of theinvention; it is to be understood, however, that these embodiments arenot intended to be exhaustive nor limiting of the invention but aregiven for purposes of illustration in order that others skilled in theart may fully understand the invention and the principles thereof andthe manner of applying it in practical use so that they may modify it invarious forms, each as may be best suited to the condition of aparticular use.

These and other objects are achieved in a preferred vention provides apost cross-sectional configuration and material strength suitable foruse in standard wire-wrap applications as well as clip type applicationswith a relatively thin post material having qualities suitable forforming other types of connectors including those demanding springqualities. The improved method of manufacture contemplated by theinvention embraces steps of a shearing, bending and impact, extrudingoperating on the terminal post section to provide qualities of hardnessand slope to post corners which result in an improved electrical andmechanical connection between conductor wire and post with respect towire-wrap applications. The improved method of the invention furtherresults in a post construction capable 'of bearing the forces impartedby both wire-wrap and clip type procedures and furthermore of aconstruction capable of manitaining a substantial dimensional integrityto provide the necessary elastic reserve demanded by wire-wrap and cliptype connectors. In further embodiments of the invention there isincluded integral with the post and transition sections of the inventionconnector, extended portions of distinctly different characteristicsadapted for use in mounting the connector or in configurations suitablefor use in other types of connectors of disconnect or crimp type.

In the drawings:

FIGURE 1 is a perspective showing part of a point-topoint matrixincorporating the connector of the invention mounted in an insulatingboard member with examples of wire-wrap and clip type connections;

FIGURE 2 is an enlarged perspective, partially sectioned, of anembodiment of the connector of the invention including the structuralfeatures of post, transition, and latching sections thereof;

FIGURE 3 is a fragmentary elevation of the transition section of thestructure shown in FIGURE 2;

FIGURE 4 is a cross section taken along lines 44 of FIGURE 3;

FIGURE 5 is an enlarged perspective showing an embodiment of theterminal post construction contemplated by the invention integrallyformed with a transition section and a mounting section and furthershowing a typical wire-wrap positioned on the terminal post section;

FIGURE 6 is an enlarged end elevation of the device shown in FIGURE 5 asviewed from lines 66;

FIGURE 7 is an enlarged section of the device shown in FIGURE 5 asviewed from lines 77 therein included to show the geometrical and metalcharacteristics achieved in one embodiment of the terminal post of theinvention along with the particular contact interface achieved be tweenconductor wire and terminal post corners;

FIGURE 8 is a perspective of an actual progression showing the variousforms during manufacture of one embodiment of the invention includingone preferred embodiment of the post section;

FIGURE 9 is a section of the tooling utilized to practice the method ofthe invention in achieving the novel post construction contemplated;

FIGURES 10, 11, 12 and 13 are enlarged elevations of the die faces ofthe tooling shown in FIGURE 9' depicting the impact extrusion steputilized by the method of the invention;

FIGURES 14 and 15 show elevational and cross sectional views,respectively, of an embodiment of the invention including the novel postsection integrally formed with a mounting section having spring tabmembers for mounting and locking a connector within an insulating boardmember shown in section;

FIGURE 16 shows an elevation of an embodiment similar to that of FIGURES14 and 15 adapted for use in thin board members shown in section;

FIGURE 17 shows an elevation of an embodiment similar to that of FIGURES14 and 15 including dual post sections oppositely oriented with respectto an insulating board member shown in section;

FIGURE 18 shows a partial section of elevation of yet a furtherembodiment of the invention including the novel post construction andintegrally formed therewith a spring section adapted for accommodating adisconnect connector of the pin type;

FIGURE 19 shows a perspective of an embodiment of the inventionincluding the novel post construction integral with a leaf typeconnector spring;

FIGURE 20 shows an elevation of a further embodiment including theterminal post of the connector in connection with a mounting sectionhaving a different locking feature; 1

FIGURE 21 shows an elevation of the embodiment of FIGURE 22 with afurther feature to accomplish connector mounting in conductive mountingmembers;

FIGURE 22 shows an elevation of a connector embodiment featuring thepost construction of the invention in combination with a crimp type wirebarrel;

FIGURE 23 shows a perspective of a number of devices of the type shownin FIGURE 22 crimped to a number of conductors;

FIGURE 24 is a plan view of yet a further embodiment including aterminal post section and an integral mounting section carrying a barreltip for use in the movable board of a patchboard device;

FIGURE 25 is a perspective of an alternative embodiment of terminal postespecially adapted for use with clip-on type connections;

FIGURE 26 is a section of the post of FIGURE 25 taken along lines 25-25;

FIGURE 27 is a perspective of an actual progression showing the variousforms during manufacture of the device of FIGURE 25; and

FIGURES 28-32 are fragmentary sectional enlarged views of the steps ofmanufacture preferred to achieve the post configuration shown in FIGURE25 The above outlined general objectives and specialized criteria ofwire-Wrap and clip type point-to-point electrical connectors should bekept in mind in order to more fully appreciate the advantages inherentin the means and method contemplated by the invention. An additionalconsideration not heretofore appreciated should be also kept in mindinvolving the connector of the invention relative to its capability toperform a connection of a distinctly different type; namely, aconnection having requirements of geometry and material characteristicsbasically incompatible with those of Wire-wrap or clip type connections.FIGURE 1 showing one embodiment of the invention mounted in aninsulating board member to form a point-to-point wiring matrixdemonstrates the foregoing. The insulating board member 10, only acorner of which is shown, represents for illustration the rear bay of astandard plugboard assembly of the type shown and described in US.Patent No. 2,975,395 issued Mar. 14, 196 1, in the name of G. C. Sitz.Fitted in apertures 12 of board are connectors 70 different from thoseshown in Sitz having upper sections 20 defining a pointto-point wiringmatrix and lower sections 76 extending on the other side of board 10defining flexible contact spring members 78. Each connector 70 isintegrally formed of relatively thin conductive sheet material as forexample, brass, to provide an electrical path through board 10. Anintegral latching section 72 at mounting section 74 having locking tabs77 is included in the connector structure to hold or secure the uppersection 20 and the lower section 76 against axial movement. The uppersection 20 includes a post 22 having characteristics which will bedescribed in detail hereinafter accommodating standard wire-wrap or cliptype applications to achieve an electrical connection between a givenconnector 70 and an electrical conductor from some external circuit onother structure. An example is depicted in FIGURE 1 wherein a conductor90 is shown having wire-wrap turns 92 forming a connection with the post22 of 20 and thereby With a connector 70. The post 22 further includesfeatures accommodating the application of other types of point-to-pointwiring devices such as the clip 94 serving to interconnect conductor 96to a connector 70. It is, of course, to be understood that in the usualcase one type of wiring interconnection, wire-wrap, clip or other willusually be employed throughout for a given point-to-point wiringapplication relative to the same wiring matrix.

With the various post sections 22 wired to define electrical circuits onone side of board 10 as indicated in FIGURE 1, the board 10 may beinserted in a plugboard assembly of the type above referred to anddriven into a position wherein contact pin members such as 98 are drivento engage, deform and hold, under spring pressure as indicated, thecontact spring members 78 of the sections 76 of connector 70. From theforegoing it should be apparent that connector 70 provides a connectorfor point-to-point wiring application capable of directly accommodatingdistinctly different types of connections without resort to a number ofseparate connectors as in Sitz and the problems of reliability inherentin the additional connection necessitated thereby. While the connectorstructure depicted in FIGURE 1 includes a resilient spring member, therelative thinness of the material employed permits other connectorconstructions of a type capable of being formed during connectorinstallation in an insulating board, such including integral metal tabportions to lock the connector into position into the board or performother spring functions and, in certain instances, to contact printedcircuit paths in a manner suitable for dip or other type solderingprocedures. Yet other uses include a connector structure having aterminal post on one end and a rounded barrel tip on the opposite end toprovide the contact surface for members mounted in the front bay orboard of an assernbly having the use and function of the assemblydescribed in the Sitz patent, above mentioned. Embodiments of theinvention exemplifying these uses will be described with respect toFIGURES 14-24 hereinafter.

As a differently expressed brief summation of the foregoing, connectorshaving spring, crimp, or folded tab or barrel features are more easilymanufacturable to have desirable characteristics if the Wall metalmaterial utilized be relatively thin initially, While other types ofconnectors serving wire-wrap or Clip connections demand a certaindimensional thickness most readily answered by the prior art use ofrelatively thick metal stock. The present invention solves this problemby a post construction of relatively thin metal stock having aconfiguration and hardness suitable to support both wire-wrap and cliptype connections and atthe same time answer the needs of otherconnectors.

Turning first to the aspect of the invention relating to the terminalpost construction of the invention, reference may be had to FIGURES 2,3, and 4. In FIGURE 2 member 20 will be recognized as the upper portionof connector 70 shown in FIGURE 1, including a post section 22 andintegral therewith a transition section 60 and a portion of latchingsection 72. As further apparent from FIGURE 1, section 22 is useful tomechanically support and electrically connect a conductor with connector70; while section 60 operates to support and electrically connect post22 with section 72, which in turn serves to latch the post and 70 withinan insulating board.

Member 20 is formed of relatively thin metal stock such as brass toinclude post sections 22 defining wall members 24 and 26 interconnectedby a wall member or web 28 with the post axially projecting fromtransition section 60 and section 72. The relative planar disposition ofthe integral wall members 24, 26 and 28 serves to resist rotational orradial as well as axial force moments in the same manner as the wellrespected I beam structure; both being eificient alternatives to solidbeams with respect to strength. As a further feature, post section 22includes sharp corners or edges 32, 34, 36 and 38 as establishing theabrupt edges necessary for wire-wrap. Wall surfaces of 24, 26 and 28 arealso utilized for accommodating a conductor driven thereagainst by cliptype connectors; the surface of wall 28 being preferred. It iscontemplated that the interior surfaces of the post 22 may, in certaininstances, be utilized to accommodate conductors fastened thereto byclip members.

Transition section 60 includes a flared or tapered, curved configurationof the same thickness of post 22 which is gradually increased in widthto join at 62, the generally tubular latching section 72. As shown inFIG- URES 3 and 4, the transition section is rounded in cross section toinclude a .general taper of angle C as measured between planes parallelto a longitudinal axis of post 22 and parallel to the surface of 60. Theobject of transition section 60 is to resist relative rotational,transverse or axial post displacement relative to the section 72. Aswill be appreciated by those skilled in the art, an angular dispositionof transition wall 60 with angle C approximating 30 operates to providesupport of post section 22 in an efficient and reliable manner. Theenlargement of the surface area of section 72 achieved by the increaseddiameter of 60 operates to facilitate mounting of the connectorstructure against rotation or other movement relative to the insulatingboard member and, additionally, provides -an available space 73 capableof accommodating the insertion of contact pin members as in certainembodiments of the invention to be described hereafter. Section 72,which may include a variety of different configurations, is shown inFIGURE 4 as D shaped to complement the mounting section, which fits inan interlocking relationship the D shaped apertures of a standardplugboard.

The particular geometry and material characteristics of the post section20 may be more fully explained by drawing reference to the wire-wrapinstallation procedure, which subjects the assembly to greater stressesthan any other point-to-point wiring application including the cliptype. Turning then to a more detailed description of the postconstruction, reference may be had to FIG- URES 5, 6 and 7. In FIGURE 5,the section 20, described with respect to FIGURE 2, is shown with aconductor 90 applied through a number of turns 92 to the post section 22thereof in a typical wire-wrap application. The functional objective ofthe connection shown in FIG- URE is, of course, to provide a path ofelectrical continuity through conductor 90 and the conductive materialof section 22; which path has characteristics of low resistance in thepresence of time, vibration, humidity, and other environmental effects.In this manner an electrical circuit path is completed from 90 toanother circuit connected to structure 70 as indicated in FIGURE 1. Theparticular wire-wrap shown in FIGURE 5 may be considered as applied bystandard wire-wrap tooling in the manner urged by Mallina, Mason orBuhrendorf, above mentioned.

The provision of end 50 on post 22, more clearly shown in FIGURE 6,serves to accommodate the entry portion of standard wire-wrap tooling.The end 50 includes two rounded portions 52 and 54 turned inwardly andradiused so as to reside within the area defined by the four corners ofthe post as viewed in cross-section. This feature operates to preventthe wire held in a wire wrap tool, or portions of the tool itself, fromsnagging on what otherwise might be sharp corners extending beyond themain body of the post at an end thereof.

In FIGURE 7 an enlarged detailed section of the post constructioncontemplated by the invention is depicted showing the post 22 to have aperipheral configuration which is substantially square with respect tothe corners thereof. The side walls 24 and 26 interconnected by bottomwall or web 28 of the post are each substantially the same width todefine an open section or slot between the side walls shown as numeral30. At the upper corners of side walls 24 and 26 are further wallsurfaces which intersect to define edges 32 and 34. At the lower cornersof walls 24 and 26 and integral with wall 28 are further edges 36 and38. It will be noted that each pair of surfaces adjoining edges 32, 34,36 and 38 define an interior angle of approximately This is indicated byangle A with respect to the surfaces of 24 and 28. More specifically,with regard to describing the sharpness of post edges, reference may bemade in terms of edge radius R shown with respect to corner 36. In apreferred embodiment of post construction, radius R is held to threethousandths of an inch with any tolerance leeway being taken up byhaving the radius less rather than greater than three thousandths. Thecontrol of angle A and radius R is important to wire-wrap applicationsfor the reasons to be discussed more fully hereafter.

A further aspect of the post construction contemplated by the inventionis indicated from the small lines within the interior portions of thepost cross section shown in FIGURE 7. These lines are based uponmicrophotographs of an actual sectioned post and represent areas ofworked metal, which provide a controlled metal hardness. Based upon aVickers diamond pyramid hardness test (15 grams), a survey of post 22indicates a hardness range of approximately to in the less densely linedareas, such as 42, and a hardness range from approximately 190 to 225 inthe more densely lined areas such as 44, 46, and 48. It is to beobserved that the post material defines relatively hard areas at eachpost edge 32, 34, 36 and 38 as well as in areas or zones surrounding theinterior U portion of the post 22. The edge hardness serves to provide abiting edge of sufiicient strength to permit a proper penetration of theconductor 90 by each edge, thus operating to increase area of contactwith the post at each edge. The hardness zones such as 44 operate tostrengthen the post construction and resist collapse of side walls 24and 26 under the forces of the wire-wrap imparted thereto.

A further material feature of post 22 is indicated as shown with respectto bottom wall 28. The curvature is in a preferred form, in the range offrom 10 to 17 with respect to angle B measured from a horizontal line toa line tangent to exterior surface 40 of wall 28. This curvature hasbeen found to be highly desirable in maintaining the dimensionalintegrity of the post 22 under the force of wire-wrap turns as well asproviding strength with respect to transversely developed forces tendingto bend the post.

The advantages inherent in the post construction above described may bebrought better into focus by reviewing the steps involved in theapplication of conductor wire 90 to accomplish a wire-wrap connection.Considering that the end 91 of conductor 90 is held fast and the wire isdrawn around post corner 36 and corner 38 in the manner indicated undera considerable force F, it will be apparent that a clock-wise torquewill be generated tending to twist post 22. The geometry and materialhardness of post 22 is such as to permit a slight twisting withoutrelative displacement of walls 24, 26, and 28 which at the same timeoffers a positive resistance such that post edges 36 and 38 will biteinto 90. The hardness of the edges of the post is such that the standardforce applied by wire-wrap procedures will not unduly crumple or shearoff such edges. The slope or sharpness of the post edges as measured byR is such as to provide a controlled penetration without severing 90under the forces involved. As is understood, the sharpness of the postedges in conjunction with angle A of wall surfaces determines the depthof penetration, which in turn determines the contact area per edge perturn. Additionally, the sharpness of the post edges and the angle A ofwall surfaces determines the interior wire face areas engaging the postedges to hold the wire against movements which could destroy the elasticreserve developed when the wire is stretched. Thus, as a turn of wire 90is applied to the post, the section I is placed in tension held by thesurface areas of the wire in contact with vertical surfaces of edges 36and 38 respectively. A section of wire II will be similarly held betweenthe horizontal surface areas of edges 38 and 32, and a section of wireIII will be similarly held between the vertical surface areas of edges32 and 34 as indicated. It will be realized that the application of legIII of the wire to edges 32 and 34 must not operate to collapse thesidewalls 24 and 26 closing space 30, thus destroying the post geometrynecessary to maintain the elastic reserve between wire and post. Thelocation of the cold work structure indicated by lines 44 as well as thecurved configuration of the bottom wall 28 conjointly serve to resistany force tending to bring post walls 24 and 26 together.

As an additional point worth noting, the relative stiffness of walls 24and 26 against closure is much greater than if the post were merely Ushaped, thus tending to bend about a longer moment arm.

It is preferred to provide a plating 49 to the exterior surface of thepost 22. Such plating may comprise a first layer of nickel approximately1.0 thousandth of an inch in thickness with an overlayer of goldapproximately 60 millionths of an inch in thickness.

During and after the application of clip type connections as shown inthe above mentioned patent application to Cobaugh, the post constructionshown in FIGURES 5, 6, and 7 operates to resist both axial andtransverse forces of application and to provide a constant dimensionalgeometry holding the clip in position. The relative thickness ofsidewalls 24 and 26 taken in conjunction with their position relative tothe disposition of a clip serves to maintain the post integrity. Thesurface 40 is preferably utilized to accommodate the wire beingterminated by the clip type procedure, although as above mentioned, anyof the surfaces, interior or exterior, may be so utilized.

While the post construction and material characteristics of the postheretofore shown and described may vary dependent upon the diameter andthe material chracteristics of the wire employed, the followingdimensions of an actual post construction are included not to restrict,but to aid in indicating relative dimensions and characteristics foundsatisfactory for a type of commonly used wire identified as No. 22 AWGSolid Strand.

Dimensions in thousandths of an inch:

Post length from end 50 to transition section 60 600 Post height, walls24 and 26 49.0 Post width, leg 28 49.0 Wall thickness, legs 24 and 2617.0 Wall thickness, leg 28 15.0

Material employed Brass Angle A, degrees 77 Angle B, degrees 13 Angle C,degrees 33 Radius R 3.0 Transition section 60, length 75.0 Mountingsection 74, largest dimension 375.0

With the geometry and material characteristics of one preferredembodiment of the novel post construction of the invention thusdescribed, the method of the invention utilized to achieve such will nowbe treated.

FIGURE 8 depicts a progression including ten steps representing stepsutilized in producing the post above described as integrally formed withthe particular embodiment shown in FIGURE 1. A further step may beconsidered as that of plating and may be performed in a standard manner.While it is fully contemplated that each of the steps shown in FIGURE 8may be performed in a non-automatic fashion, the preferred mode includesan automatic operation wherein a series of die stations I-X are arrangedto be driven in a step-by-step fashion to perform shearing-punching,coining, extruding and shearing operations on a continuously fed stripof joined connector members. Production techniques of this type aregenerally well known.

Beginning with a spool or other supply of fiat sheet metal stock asindicated by numeral 102 stations IX operate to transform sheet 102 intoa separate connector member 70 as indicated at station X. It iscontemplated that stations I-X are fixed and that sheet 102 and theprogression formed thereof is moved by carrier 103 driven by pin membersadapted to engage pilot holes 104 punched therein prior to station I. Itis further contemplated that in a manner well understood by thoseskilled in the art the die operations at each station are synchronizedby means of the pilot holes 104 operating pin members driving a diedrive initiating means.

Based upon the progression shown in FIGURE 8, the operation at each dietation I-X with respect to forming the connector shown at station X,exclusive of the post section 22 and the transition section 60 should begen erally understood. The operations pertinent to the methodcontemplated by the invention are performed particularly at stations VIand VII and to a degree at stations II and IV. The only significance ofstation I with respect to the post and transition sections is that ends52 and 54 are defined by the first shearing operation. At station IIpost edge 34 and the adjoining edge of transition section 60 are formedon one connector member while the adjacent post edge 32 and theadjoining transition section 60 thereof are formed. The operation atstation 11 serves to work-harden to an extent consistent with a shearingoperation, edges 32 and 34 of each post wall 24 and 26. At station IVends 52 and 54 are turned upwardly, which operation assures that suchends will be turned inwardly for the purposes heretofore describedduring the bending operation performed on the post section at stationVI. The operation performed at station VI serves to form transitionsection 60 into its final shape; the die faces for forming such shapebeing of the general shape of the interior and exterior surfaces of suchsection as shown in FIGURES 3 and 4. The bending of the post section 22at station VI results in a degree of work-hardening occurring in theportions of metal bent and proportional thereto. The die configurationsfor forming the post section 22 in the geometry shown at station VI aregenerally as the interior and exterior surfaces indicated in FIGURE 10;namely, U-shaped.

At station VII the critical part of the method of the invention iscarried out with the geometry of the post section including the materialcharacteristics heretofore outlined being achieved. At stations VIII-Xfurther operations are carried out to progressively form the remainingportions of the connector embodiment chosen to exemplify the method ofthe invention.

Turning now to FIGURES 9-13, there is shown a preferred form of thetooling utilized at die station VII with the die members thereof inclosure against post section 22 in the center of the figure. As a partof station VII and common with'the remaining stations there is provideda stage of relatively heavy metal stock positioned and held by stagesupport 112 seated and anchored on a tooling base 113. Stage support 112is, of course, duplicated along the various stations under portions ofstage 110. Supported and secured to stage 110 is die guide plate 114having a number of apertures therein 118, to support and position diemembers appropriate for each station. Secured in aperture 120 is member122 forming part of the lower die of station VII. Member 122 includes acentrally disposed die guide-way 124 having interior sidewalls adaptedto maintain in sliding engagement a central die member 126 having atapered extension defining die portion 152 with face 154, betterapparent in FIG- URE 10. The lower movable die member 126 is furthersupported for vertical movement by the wall surfaces of an aperture 128in stage 110. Secured to the lower portion of die member 126 and beneathstage 110 are flange members 130; the horizontal surfaces thereofserving as stops against vertical movement of die member 126 by engagingthe lower surface of stage 110 and the upper surface of die stop member136 respectively, on upward and downward movement. As will be apparentfrom FIGURE 9, the die member 126 is shown in its driven or bottomedposition. Die stop member 136 includes a central bore 140 of a diametersufficient to house a compression spring 150 coaxial with a spring guidemember 134 which is part of the movable die 126. With the dies in theposition shown in FIGURE 9, spring 150 is in compression to develop aforce tending to drive the die member 126 upwardly.

Aligned with the center-line of lower die half 126 and the upper slotportion of guide-way 124 of die guide member 122, upper die 160 iscarried in vertical movement by die carrier 162 and secured thereo bypin member 164. The lower portion of die 160 includes a taperedextension 168 having a die face 170.

Reviewing now the operation of the tooling shown in FIGURE 9, upper die160 may be considered as initially in an upward position indicated bythe dotted line while lower die 126 is in the upward position with thetapered face 125 of die member 126 resting against the tapered face 123of die guide 122 under the force of spring 150. The progression shown inFIGURE 8 may be considered as being stepped along the progressionsupport 114 with the upper die 160 being actuated to be drivendownwardly as the centerline of each post section 22 arrives at thecenterline of the dies 160 and 126 and comes to rest as shown in FIGURE10.

At this point, die 160 is operated to force the post section 22 downinto the upper portion of slot 124 of member 122 with die surfaces 172engaging edges 32 and 34 and the apex of the die surface 154 of portion152 engaging the bottom surface of post wall section 28. The downwardmotion of die 160, post 22 and die 126 continues until flanges 130 ofmember 126 bottom against the upper surface of member 136 as shown inFIGURE 9. The continued downward motion and force of die 160 drives dieface 170 working against die face 154 to perform a coining operationupon the post section 22. Thereafter, die carrier 162 will move die 160upwardly to its rest position indicated by the dotted line with diemember 126 under force of spring 150 acting through die portion 152 todrive the post section upwardly and out of slot 124; the post sectionbeing released for movement to adjacent station VIII.

Considering the final extrusion step of the method of the inventionwhich achieves the novel configuration and material characteristics ofthe post section of the invention, FIGURES 10, 11, 12 and 13 show indetail the operation of dies 160 and 126 as heretofore described. FIGURE10 represents the initial position of post 22 just prior to theinitiation of downward movement of upper die 160 carrying tapered end168 and upper die face 17, in a downward direction to engage post edges32 and 34. Post section 22 nests within the slot portion of 124 againstthe interior edges of die guide 122 being driven to such position as theconnector progression is driven along 114. The preferred shape for dieface 170 is shown in FIGURES 10-13 to include a central projection 174having a concave surface 178, faces 172 with the outer edges 173 thereofhaving a slight radius. The lower die portion 152 includes a face 154defining a convex surface. From the description given relative to FIGURE7, the characteristics and function of die faces 170 and 154 should beunderstood.

FIGURE 11 shows the next step wherein upper die 168 is driven downwardlyand within the die guide 124 to depress post section 22 along the pathof travel defined by slot 124. From FIGURE 11, it may be noted that thelength of projection 174 is substantially less than the depth of thepost section at this degree of forming. FIGURE 12 shows the next stepwherein the travel of lower die portion 152 is stopped by reason of die126 bottoming through flanges 130 against member 136. At this point, thepost section, including walls 32 and 34, is in compression in thevertical sense with the post metal between the positions in FIGURES 11and 12, outer edges 36 and 38 are driven downwardly and extruded into anextending contact with the surface 154 of lower die 152. FIGURE 13 showsthe final stage of forming wherein die 168 has reached the bottom of itstravel and the post section 22 is fully compressed into the volume thendefined by die surfaces 170' and 152. At this point it will be observedthat the rounding of edges 173 of die surfaces 172. results inrelatively sharp edges 32 and 34; a similar result occurring withrespect to edges 36 and 38 by means of the convex surface of 154.

During the downward stroke of die 168 and particularly at the point oftravel indicated in FIGURES 12 and 13, a considerable working of themetal located in the areas 44 occurs (FIG. 7). This working is inaddition to, and in a transverse sense, with respect to the initialworking of these areas occurring at the preceding station V wherein thepost section was formed into the U-shape shown in FIGURE 10. The areasproximate the post edges 32, 34, 36 and 38 each receive double working;edges 32 and 34 having been worked during the initial shearing operationand edges 36 and 38 having been worked during the shearing operation atstation VI. The center wall 28 also receives a double working; first inthe bending at station VI, and second in the forming as indicated inFIGURES 12. and 13. The hardened areas proximate the junction of wall 28and walls 24 and 26 provide a spine-like structure performing astiffening function with respect to the post.

As a result of the foregoing, the geometrical and materialcharacteristics above described with respect to post section 22 areproduced from a relatively thin metal sheet. The post constructionincludes characteristics of hardness at necessary points with resiliencyelsewhere to serve in supporting the application of both wire-wrap andclip type connections. An adequate concept of the relative dimensions ofdie faces above described may be obtained from the dimensions given withrespect to the post section of the invention. Relative to the particularsample dimensions previously recited the force applied to die member wasapproximately twenty tons through a stroke of approximately 1.5 inches.

It will be recognized that the method of bending and extruding abovetaught may be utilized to achieve a wide variety of post constructions.For example, and as to the post itself, sidewalls 24 and 26 may beadditionally extruded in a radial sense inwardly to provide a generallyX shaped cross-section. This may be accomplished by reshaping the wallsurfaces of guide way 124 proximate the post wall position at the bottomof die travel. An alternative further example, sidewalls 24 and 26 maybe additionally extruded from the shape shown in FIGURE 13 to defineaxially disposed indentations of part of the wall Width to even furtherstrengthen the post. As yet another alternative example, other shapesthan the square shape recognized as the standard wire-wrap shape bycertain segments of the industry may be formed by altering the relativewidth of sidewalls 24 and 26, and wall 28. Thus, a generally rectangularpost shape may be obtained by decreasing the relative width of walls 24and 26, and increasing the relative width of wall 28. These and manyother equivalent structures may be obtained by following the method ofthe invention above outlined. In an alternative form of the invention tobe hereinafter given, yet another type of post is contemplated usingcertain essentials of the above method.

It should be appreciated by those skilled in the art that, because ofthe relatively thin sheet material utilized in the post construction ofthe invention, a considerable number of integral mounting and associateconnector configurations having widely different functions are possible.The more significant connect-or shapes considered as part of the presentinvention are included in FIGURE 1, previously described to introducethe advantages of the invention, and in FIGURES 14-24 to be nowdescribed.

Turning to FIGURES 14, 15 and 16, an embodiment of the invention isshown adaptable for use in point-to-point wiring applications of thetype wherein a matrix of terminal posts are variously interconnected onthe same relative side of an insulating board with one or severalwire-wrap or clip-on type connections made per post to join conductorsand thereby complete signal paths. In this type of application, onetermination might be made to one post with wire laid in coordinatefashion between the matrix of posts to another post with separatefurther conductors being wire-wrapped or clipped to each of the posts.In FIGURE 14, 200 represents an insulating board apertured as at 202 toreceive a connector 204, including a terminal post 22 integral withtransition section 60, identical to the post described above withrespect to FIGURE 2. Further integral therewith is a post mountingsection 206 similar to the mounting section 74 above described,including spring-like tab members 208 and 210 at the end adjacenttransition section 60, and similar members 212, 214 at the opposite endthereof, similar to latching section 72 above described. With thisconstruction, connector 204 may be fitted and latched or locked intoboard 200 by depressing the tab members at either end inwardly towardthe center of mounting section 206 and inserting the mounting section206 within aperture 202. Thus, if a rearward mounting is called for,wherein the post section 22 must enter aperture 202, spring tabs 208 and210 may be depressed inwardly, the connector 204 inserted to a pointwherein spring tabs 212 and 214 block further movement by contact withthe bottom surface of board 200; the tabs 208 and 210 then beingreleased from confinement within aperture 202 to spring outwardly totheir normal position to lock 204 within the board. With theconstruction shown in FIGURES 14 and 15, connector insertion from eitherside of board 200 is possible. As a further advantage inherent in theembodiment of FIGURES 14 and 15 and with slight modification, theconstruction of the connector may be utilized for, or with, insulatingboards of different thickness. This is shown in FIGURE 16 whereininsulating board 220 is approximately half the thickness of board 200. Aconnector 224 similar to that shown in FIGURES 14 and 15 may be insertedfrom either side of board 220 by an appropriate depression of springtabs 228230 or 232234. It will be noted that the only difference in thestructure of 224 lies in the relative axial thickness of the springtabs. The only substantial limitation on the thickness of thinness ofboard which may be accommodated is that mounting section 226 must beleft with a sufficient bearing area to properly support 224 in thepresence of stresses placed thereon upon application of a conductor topost 22 and the tab members must be of a material width sufficient toperform the latching function.

A further embodiment of the invention is shown in FIG- URE 1'7 whereinthe now familiar post section 22 and transition section 60 areduplicated on each side of an insulating board 240. In this embodiment,connector 244 is provided with a mounting section 246 having at one endspring tabs 2 48 and 250 identical in structure and function to thespring tabs above described with respect to FIGURES l416, and at theother end, further identical spring tabs 252 and 254. Connector 244 may,of course, be inserted from either end through aperture 24-2 of board240 to accommodate point-to-point wiring application on both sides ofboard 240.

FIGURE 18 depicts another highly useful connector assembly incorporatingthe post construction of the invention with an integrally formed springsection having a disconnect function somewhat different from the type ofspring embodiment shown in FIGURE 1. Thus, in FIG- URE 18, an insulatingboard 260 is shown having a connector assembly 264 secured in anaperture 262 therein capable of accommodating point-to-point wiringterminations on one side and a pin type disconnect on the other sidethereof. Connector 264 includes at the upper end post section 22,transition section 60 and a central mounting section 266 having springtabs 268 and 270 adjacent being driven and extruded. During thetransition of post section 60 and spring tabs 272 and 274 at theopposite end thereof to latch 264 within aperture 262. As shown inFIGURE 18, section 266 includes further, struck out spring tab members276 axially disposed within mounting section 2 66. The disposition ofspring members 276 is such as to make contact with a pin member 280inserted within the mounting section 266. As indicated, the insertion ofpin member 280 will form a contact path from a conductor 282 to one orseveral conductors, not shown, wirewrapped or clipped to post 22. Thisembodiment is preferred in application wherein there are heightlimitations in conjunction with disconnect requirements.

FIGURE 19 depicts a further embodiment of the invention featuring anintegrally formed spring portion suitable for performing disconnectfunctions of a different type. Secured in insulating board 300 throughaperture 302 thereof is a connector 304 having a mounting portion 306and spring tabs 308, 310, similar to those above described, cooperatingto support and latch 304 within board 300. On one surface of board 300and extending from 306 is the post section 22 and transition section 60as above considered. On the opposite side of board .300 is an integrallyformed spring structure 316 including opposing, curved cantilever springarms 318 and 320, which are relatively flat as is shown in FIGURE 19.The connector embodiment shown in FIGURE 19 is well suited to accomplisha direct connection from conductors mounted on post 22 to the circuitconnected to a conductor path such as 319, which may be part of printedcircuit paths on a printed circuit board 324 housing a number ofcomponents. With embodiments of this type, an insulating card carryingprinted circuit path connected to resistors, transistors, capacitors orthe like may be made common to one row of terminal posts or to severalrows of posts in both the X and Y directions of the post matrix; thecard being both mechanically supported and electrically connected bymeans of spring arms 318 and 320. With arrangements of this type for agiven matrix board, it has been found useful in certain applications toinstall several piggy-back component insulating cards such as 324through mechanical and electrical connections with an appropriate numberof connectors 304; the remaining and majority of the connectorsassemblies of the matrix being one type shown in FIGURES 14-16.

In FIGURES 20 and 21 there is shown yet a further embodiment of theinvention specialized to provide an even more secure mounting thanprovided by the embodiments heretofore described, and additionally, afurther capability with respect to direct connections to planarconductive paths disposed on one side of a matrix board. The embodimentsshown in FIGURES 20 and 21 have considerable utility in situationswherein a number of wire-wrap or clip type terminations are to be madeat relatively separated locations, as, for example, the use in theconnections formed on a television chassis. The particular embodimentshown in FIGURE 20 is mounted in an insulating board 330 and held withinaperture 332 thereof by means of mounting section 336, a peripheral bead338 and folded tab members 340 and 342. The bead portion 338 disposedadjacent transition section 60 represents a slight enlargement of thediameter of mounting section 336. Tab members 340 and 342 having aninitial diSpOsition as indicated by the dotted lines in FIGURE 20 arefolded inwardly against the lower surface of board 330 to latch 334against displacement. The use of tab members 340 and 342 maybe desirableas an alternative to the lower spring tabs shown and described withrespect to the embodiments in FIGURES 14-17 due to the built-inadvantage of accommodating tolerance variations in board thickness.Thus, considering the embodiment shown in FIGURE 20, the connector 334could be made to accommodate a considerable variation in the thicknessof the board 330 larger than that shown; the thickness difference beingtaken up by merely bending a relatively shorter length of tab members340 and 342. As yet a further advantage of the construction shown inFIGURE is the possible use of tab members 340 and 342 for soldering tabsto a plated or printed circuit conductive path such as 346. To this enda small turned down portion 343 of one or both tabs 340 and 342 may beprovided to accommodate dip solder techniques utilized in a manner wellunderstood by those skilled in the art.

The embodiment shown in FIGURE 21 is quite similar to that shown inFIGURE 20 including in a connector structure 354, a mounting portion356, head 358 and tab portions 360, 362 all integral with a transitionsection 60 and post section 22. The use shown in FIGURE 21 differs withrespect to the board member 350 which may be of steel Or otherconductive material. An insulating washer 364 is provided comprised ofnylon. Teflon or similar materials, sufiiciently pliable to be snappedwithin aperture 352 and yet sufficiently stable with respect to materialflow to hold the connector 354 in position anchored by the overlap ofhead 358 over the top portion of 364 and tab members 360 and 362 turnedinwardly against the bottom surface of 364. To further assure 354 beinglocked within board 350, it is preferred to have the outer diameter ofbead 358 and the length of tabs 360 and 362 such that there is anoverlap as shown in FIGURE 21 with respect to the diameter of aperture352.

Turning now to a further useful embodiment utilized to disclose thepreferred mode of practicing the invention, FIGURES 22 and 23 depict anarrangement for interconnecting conductors utilizing wire-wrap orclip-on type connections to conductors having different characteristicssuch as those of stranded or relatively large diameter wire. Aconsiderable problem calling for a connector of this functionalcapability has developed from the use of large and relatively expensivewire-wrap and clip-on type automatic machines which cannot perform asplice between conductor wires and which must invariably work through aterminal post interface. In FIGURE 22 a section of insulating blockmaterial 370 is shown apertured at 372 to receive a connector 374 havingat one end a terminal post 22 secured by a transition section 60 to amounting section 376 interlocked into board 370 by spring tabs 378, 380,382, and 384 of the type heretofore described. Further integrally formedwith mounting section 376 is an extended wire barrel portion 386defining a volume capable of receiving conductor strand 392 of aninsulated conductor 390 therein. The relatively thin material utilizedfor the upper portion of the connector 374 is ideally suited for use informing wire barrels having characteristics suitable for crimpingtechniques. With respect to barrel portion 386, the relative thinness ofthe connector material permits the use of a number of types of crimps.For example, an F crimp may be applied to electrically and mechanicallysecure conductor 390 to form an electrical path to some other pathconnected to post 22 through either wire-wrap or clip-on typeconnections. FIGURE 23 shows an extension of block 370 to accommodate aplurality of connectors 374, each in turn crimped through the wirebarrel section 386 by an F crimp 394 to conductors 390. The particular Fcrimp illustrated is more completely described in US. Patent Reissue No.24,510 issued Aug. 5, 1958, to James C. Macy. Blocks such as 370containing one or dozens of connectors 374 are quite useful inconjunction with large point-to-point wiring circuits having one ordozens of auxiliary or associated circuit paths connected to auxiliaryequipment via stranded or enlarged diameter cables.

in the embodiment shown in FIGURE 1, the novel terminal post of theinvention is incorporated with a contact spring member adapted for usein the rear bay of a plugboard assembly. It is also contemplated thatthe invention may include a connector construction featuring a terminalpost on one end and on the opposite end a barrel tip member having thefunction of member 98 as shown in FIGURE 1. A device of this type isused in the front bay or movable board of a plugboard assembly with thebarrel tip being driven through the movement of the board to engageconductive spring members in the manner described in the Sitz patent.The terminal post portions of each assembly are then pattern wired withleads terminated through wire-wrap or clip-on procedures to duplicatethe function of the patchcords described in the Sitz patent. FIGURE 24shows an end view of a movable patchboard 400, having mounted thereinone of a number of connectors 404 through an aperture 402 through theboard. Board 400 is typically of an insulating material such as diallylphthalate. The front of the board or the face which is placed adjacentto a rear bay or board contact spring array is oriented upwardly in thefigure. The connector 404 includes a central mounting portion 406similar to the mounting portion 74 shown in the embodiment of FIGURE 3.As an integral extension from 406 is an upper barrel tip portion 408supported by an integral transition portion 410 similar to transitionportion 60 shown and described with respect to FIGURES 2-4 above. Thebarrel tip 408 has the function of engaging a contact spring in anopposing rear bay such as spring 78 shown in FIGURE 1, to provide aconductive path from the lead associated with the contact spring throughthe barrel tip to 404. At the edge of portion 406 and its junction withtransition portion 410 is an outward projection 412 which operates toengage the face of board 400 to lock 404 against axial movement downthrough the aperture.

At the opposite end is a further integral extension of 406, including aportion 414 having a pair of tabs 416 extending outwardly from the bodythereof to engage the board underface to prevent axial movement throughthe aperture in the opposite direction. In use, the assembly 404 isinserted downwardly through the aperture to a point wherein the tabs 416snap outwardly to lock the assembly within the board. Extending as anintegral piece from 414 is a terminal post 22, supported by a transitionsection 60, both identical to the similarly numbered parts described andshown relative to FIGURES 1-7.

The connector of FIGURE 24 is manufactured by a method similar to thatshown in FIGURE 8 with progressive operations being performed on flatstock material to achieve the geometry represented in FIGURE 24.

Turning now to an alternative embodiment of the terminal postconstruction of the invention, FIGURES 25 to 32 depict a postconstruction and method of manufacture for a post of relatively thinsheet material formed without a central channel.

As can be seen from FIGURE 25, a connector 420 is provided including anon-channeled forward terminal post 422 supported by an integraltransition portion 460 joining a support portion 462 similar to themounting sections 206 shown with respect to FIGURE 14. The mountingsection 462 is utilized in the manner indicated in FIGURE 14 to latchconnector 420 within an aperture in an insulating panel board. It iscontemplated that as in the above case, assemblies 420 could be moldedinto insulating boards rather than fitted into pre-formed apertures; inwhich event the mounting section such as 462 could be considerablysimplified by removal of the latching spring members. The transitionsection 460 is similar to the transition sections 60 heretoforedescribed.

Post 422 as shown in FIGURES 25 and 26 differs from the postconstruction heretofore described, in that it is of a rectangularconfiguration with respect to cross-section rather than of a squareconfiguration. More importantly, post 422, as compared with post 22, isnot channel, but is solidly formed, although not of solid sheetmaterial. Like post 22, the alternative embodiment includes three walls,but such are forced together along the post length. The construction ofpost 422 may at times be preferred to that of the construction of post22 above described with respect to clip-on type applications. In certaininstances and with either the larger sizes of conductive cable or with17 cable having an especially tough insulating material, the stressesdeveloped by the application of the Cobaugh clip are such as to make theconstruction of the terminal post shown in FIGURES 25 and 26 bettersuited.

As will be hereinafter demonstrated, the method of forming connector 420is similar to the method above described with respect to terminal post22. As can be seen from FIGURE 26, the cross-sectional area of post 422is such as to define a rectangular configuration with side surfaces 426and 428 separated by top and bottom surfaces 430 and 432, respectively.The abutment of pairs of surfaces defines four parallel edges or cornersextending along a substantial length of the post. As will be hereinafterdescribed, the method of forming post 422 leaves distinct zones ofhardness in the pattern indicated by the small lines in zones such as440 and 442 in FIG- URE 26 due to the working of the material whichoccurs as fiat, thin sheet stock is transformed into the configurationshown. The zones of relatively hard material, 440 and 442, serve tostiffen substantially the post against axial bending movement in use.The particular extruding step of the method of the invention folds thewalls together to leave abutting surfaces 443 and 438 which, as is shownin FIGURE 26, are in a close interlocking engagement. This has beenfound to rigidify the post by preventing relative movement between wallswhen the post is loaded. The post end 422 is bevelled inwardly to defineentry for tooling and a clip or clips driven thereover.

FIGURE 27 shows a progression depicting the steps of the method toproduce contact members having the alternative terminal postconstruction shown in FIGURES 25 and 26. As a comparison of FIGURE 8will show, the connector embodiment shown in FIGURE 27 is identical toconnector 70 with the exception that different terminal postconstruction is used. Reference may be had to the description of thesteps of the invention relative to FIGURE 8 for a more completeunderstanding of the method hereinafter described in an abbreviatedform. Reference may also be had to the description of the method of theinvention relative to FIGURES 9-13 with reference to the various diestations I-X and the operations performed thereat.

As can be seen from FIGURE 27, operations performed at stations I, II,III, IV, V, and VI thereof are substantially identical to the operationsperformed to produce the connector 70 at similarly identified stationsin FIGURE 8. As the single difference up through station VI, the edge ofthe strip material 448 is blanked to define two closely spaced small Vindentations shown as 450. This blanking and the forming at station VIIIof FIGURE 27 is such as to provide the bevel of end 424 shown in FIGURE25. As the progression leaves station VI, the terminal postcross-sectional configuration is identical to that shown in FIGURE 10with respect to its U- shape. At station VII, an alternative step toprovide the alternative embodiment and post 422 includes a pre-closingof the channel of the U. At station VIII there is a further step offlattening-extruding and swaging the end 424. Stations IX and X ofFIGURE 27 are as heretofore described with respect to FIGURE 8.

Turning now to FIGURES 28-32, the foregoing alternative method toprovide the alternative construction of the terminal post will now bedescribed in detail. FIG- URE 28 shows a partial sectional end view ofthe tooling utilized at station VII, including a die carrier 470, anupper die 474 secured to 470 by a pin 472. Carrier 470 and die 474 aredriven in the path indicated in FIGURE 28 in the same manner as the dieand die carrier shown and described with respect to FIGURE 9. The bottomface 476 of die 474 includes a relatively wide, flat section and in thecenter thereof a die face 478 better shown in FIGURE 29, to comprise aconcave V having its widest portion such as to slightly overlap thewidest portion of the lower die face beneath 474. Die 474 is drivenagainst a lower die 480 supported in a die guide plate 482 and by astage 484. As compared to the tooling shown in FIG- URES 9-13, stage 484is fixed against downward travel to thus offer a solid resistance to themetal being worked between the die faces. Lower die 480 includes arelatively wide upper surface 486 and, disposed along the center line ofupper die travel, a die face 488 consisting of a rectangular channel.This is better shown in FIGURE 29 which depicts the upper die in traveldownwardly to perform the method step of pre-closing. As can be seenfrom FIGURE 29, the post 422 is at that point in the U shape provided atstation VI. FIGURE 30 depicts the upper die in closure against 422 andlower die 480. This step serves to produce the cross-sectionalconfiguration indicated in FIGURE 30, which operates to close the sidewalls of 422 inwardly and into abutment. During the operation depictedin FIGURE 30, additional working of the material in the side and bottomwalls takes place. The material of 422 has, of course, been pre-workedto an extent by the preceding steps at stations II-VI.

Following the step shown in FIGURE 30, the dies 474 and 480 are, ofcourse, opened, and the work piece is transferred to the next station,station VIII. FIGURE 31 depicts a fragmentary view of the tooling atstation VIII to include an upper die 490, which has an axis of travel asshown and is supported and operated as generally heretofore described.Die 490 includes a flat face 492 of a width to extend over the die faceof a lower die face 494 of a lower die 496. As can be seen from FIGURE31, the lower die face is a channel of rectangular cross-section havingrelatively sharp corners. FIGURE 32 depicts the ends of dies 490 and 496which include faces 491 and 497, respectively, each sloped inwardly toaccomplish the bevelling of the end of the post into the configuration424 as shown in FIGURE 25. Thus, face 491 of die 490 is sloped inwardlysuch that, as the die is driven to bottom against the terminal post, theend thereof is swaged as indicated against face 497. The result of thestep depicted in FIGURES 31 and 32 is to flatten and extrude the postand swage its end from the configuration shown in FIG- URE 30 to theconfiguration shown in FIGURE 31. The force driving die 490 is madeconsiderable in order to force the post material into the relativelysharp corners defined by the die faces in closure. It has been foundthat the foregoing operates to provide interlocking faces of thesurfaces within the post.

The foregoing embodiments of the invention demonstrate the advantagesinherent in the construction and method of the post section of theinvention. In each instance with respect to the embodiments includingtab or spring extensions and particularly, the crimp barrel extension,manufacture has heretofore been extremely diflicult in the respect tothe provision of an integral structure having a wire-wrap or clip-ontype terminal post.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

We claim:

1. An improved method of forming an electrical terminal post of the typeadapted to receive electrical conductors applied thereto comprising thesteps of shearing a flat metal sheet to define the surface area of aterminal post, bending the sheared sheet into a generally U-shaped postconfiguration having spaced apart parallel side walls and impactcompressing the U-shaped post configuration between dies within achannel having fixed side walls confining the said parallel side wallsto a point of extrusion of the outer edges of the post configuration ina direction 19 transverse to the axis of bending to form four sharpedges at the post periphery.

2. A method of forming an electrical terminal post of the type utilizedfor wire-Wrap or clip-on type connections comprising the steps ofblanking a generally rectangular surface area to define a post surfacearea by shearing, bending the sheared surface area about the centerlineof its longitudinal length into a generally U-shaped post configurationhaving spaced apart parallel side walls, impact extruding said U-shapedpost configuration within a channel having fixed side walls confiningthe said parallel side walls by moving dies including a die portionextended between said parallel side walls to effect an extrusion of saidpost configuration in a direction transverse to the length of the postsurface area to define sharp corners at the extreme edges of the postsurface area.

3. A method of forming extremely sharp edges of hardened material of thecorners of a U-shaped terminal post including the steps of striking theupper surfaces of the post by an upper die including faces radiused withrespect to a die channel to define sharp angles, driving said post bysaid faces downwardly against a lower die face radiused with respect toa die channel having fixed side walls confining said post to definesharp angles, suddenly stopping movement of said lower die face to drivethe upper die to impact extrude said post and cause material flow intosaid sharp angles as defined by said dies and the fixed side walls ofthe channel.

4. An improved method of forming an electrical terminal post of the typeadapted to receive electrical conductors applied thereto comprising thesteps of shearing a fiat metal sheet to define the surface area of aterminal post, bending the sheared sheet into a generally U-shapedconfiguration, impact compressing the upper Walls defining the U-shapedconfiguration to fold such Walls into closure along one edge, and impactcompressing the closed configuration to a point of substantiallycomplete closure of the post with extrusion of post material in adirection transverse to the axis of bending to form four sharp edges atthe post periphery.

5. A method of forming an electrical terminal post of the type utilizedfor elipon type connections comprising the steps of blanking a generallyrectangular surface area todefine a post surface area by shearing,bending the blanked surface area about the center line of itslongitudinal length into a generally U-shaped configuration, andcompressing said U-shaped configuration in a direction transverse to thesaid length to a substantially closed configuration and then providingan extrusion of the material of said post to define sharp corners at theextreme edges of the post surface.

References Cited UNITED STATES PATENTS 2,116,269 5/1938 Kobzy 29-6302,759,166 8/1956 Mallina 17494 2,870,241 1/1959 Mason 17494 2,873,4342/1959 Drum et al 2963O 2,943,293 6/1960 Bucher et al. 29-630 3,142,8918/1964 Travis 339-276 3,283,291 11/1966 Krol et a1 339-276 3,303,2672/1967 COutu et al. 29630 CHARLES W. LANHAM, Primary Examiner.

E. M. COMBS, Assistant Examiner.

US. Cl. X.R.

